1. Field of the Invention
This application relates generally to a bicycle wheel and hub and, more specifically, to a release mechanism for a bicycle wheel.
2. Description of the Related Art
Bicycle wheels have long included a wheel rim connected to a generally cylindrical hub by multiple spokes extending radially outward from the hub. A traditional spoked bicycle wheel is illustrated in FIG. 21, and has a rim 210, a hub 220, and a plurality of spokes 250 extending therebetween. Various wheel configurations have been attempted to achieve desirable wheel attributes of reduced weight, reduced aerodynamic drag, or increased lateral stiffness over a traditional spoked bicycle wheel. However, these proposed improvements typically result in certain drawbacks.
For example, in a typical attempted light weight wheel, a reduction in weight requires a corresponding reduction in wheel stiffness. Conversely, with an attempted increased rigidity wheel, such as by increasing the number or size of spokes, increased weight and increased aerodynamic drag are often undesirable by-products of the increased rigidity.
Often, attempts to decrease aerodynamic drag, such as by incorporation of an aerodynamically sculpted “tall” rim, or incorporation of a single disk in the place of spokes, have undesirable side effects. For example, while aerodynamic drag may be reduced with a tall rim or disk wheel, the rideability of these wheels suffers. Wheels with tall rims or disk wheels are difficult for a rider to control in side winds. They also often have a higher moment of inertia than a traditional spoked wheel, so require more energy to accelerate to a given rotational speed. Moreover, tall-rimmed wheels are often relatively vertically stiff, and therefore transmit even small bumps and surface irregularities to the rider, resulting in a harsh ride.
Bicycle wheels are often coupled to dropouts on a bicycle frame or frame fork by a release mechanism. Typical release mechanisms include a rod having end nuts with surfaces suitable to clamp on the dropouts and a cam mechanism to place the rod in tension between the dropouts and compress the wheel hub between the dropouts. The cam mechanism is typically positioned outside of the dropout, where it is subject to contact by debris, obstacles, or other bicycles. In many release mechanisms, the clamping force exerted by the cam can be adjusted by tightening or loosening an adjustable end nut. However, this adjustment requires a two-handed operation on often dirty or greasy wheel components.